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Additional views for lock investigations

slookin — Tue, 04 Dec 2007 08:06:53 +0000

The lock analyses is one of important step in problem detection, also lock analyses can help to improve performance.

The standard views for analyses is: v$lock and v$session_wait

But Oracle Corp. suggest use additional views for more powerful and fast lock analyzes:

dba_waiters - show all the sessions waiting for locks and the session that holds the lock.

dba_blockers – show all the sessions that have someone waiting on a lock they hold, but that are not themselves waiting on a lock.

dba_lock – has a row for each lock that is being held, and one row for each outstanding request for a lock or latch.

dba_kgllock – auxiliary view containing the KGL locks and pins.internal (slow) view similar as dba_lock.

dba_dml_lock – has a row for each DML lock that is being held, and one row for each outstanding request for a DML lock. It is subset of dba_lock.

dba_ddl_lock – has a row for each DDL lock that is being held, and one row for each outstanding request for a DDL lock. It is subset of dba_lock.

The catblock.sql should be used for create such views. You can run it from sqlplus under sys account: @$ORACLE_HOME/rdbms/admin/catblock.sql

Documentation:

Oracle 9.2i

http://download.oracle.com/docs/cd/B10501_01/server.920/a96536/ch53.htm#1005731

Oracle 10g

http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/scripts002.htm#sthref4200

Oracle 11g see The Hang Manager utility

http://download.oracle.com/docs/cd/B28359_01/server.111/b28281/hafeatures.htm#sthref81

Host credentials when using DBcontrol 10gR2 on Windows

slookin — Mon, 15 Jan 2007 20:08:09 +0000

Some operations via web interface require a Host credentials.

You can use «oracle owner» user or create additional user, but you should give additional specific system privilege for this user: Log on as a batch job .

How you can it:

1. Go to Start > Control Panel > Administrative Tools > Local Security Policy
2. Open Security Settings > Local Security Policies > User Rights Assignment
3. Double-click on Log on as a batch job from the list of privileges in the right pane.
4. Click on Add User or Group … and enter the name of the OS user whose credentials are being used as the preferred credentials for the host.
5. Click ‘OK’ twice.

Non-interactive (silent) install Oracle

slookin — Mon, 06 Nov 2006 19:41:57 +0000

The non-interactive (silent) installation Oracle’s products are very usefully if you going to deploy on multiple servers or your server doesn’t have GUI.

You should complete following speps for install Oracle’s products in silent mode:

1) Prepare response file, this file consist answer on question which would answered in dialog mode.

You can choose on of two variant for this action:

a) Edit template for response file (folder response in your installation CD)

b) You can run test installation with recording all answers into file (this feature available from 9.2 version).

setup -record -destinationFile

2) Second step – it is running Universal Installer in silent mode:

setup -silent -destinationFile

Also, if you want deinstall product in silent mode – use following command:

setup -deinstall -silent -responseFile

This short instuction tested on Oracle RDBMS 10g release 2 and Oracle RDBMS 9i release 2 on windows-32 platform, but you can use this advice for any platform and for other version of products.

Additional information:

Oracle Official Documentation: Oracle® Universal Installer and OPatch User’s Guide

Article from OTN: Mass Software Deployment with Oracle 10g

How-To: determinate oracle patch version

slookin — Wed, 30 Aug 2006 06:57:24 +0000

For determinate current patch version you should use following:
a) select * from v$version; (Oracle9i Database Reference Release 2 (9.2) Part Number A96536-02)
b) select * from dba_registry; (Oracle9i Database Reference Release 2 (9.2) Part Number A96536-02)
c) readme.html from patches (can be extract from patch bundle or downloaded from metalink)

Первый шаг.

select banner from v$version;
все компоненты должны иметь одну и туже версию (9.2.0.x).

с не большим исключением – после инсталяции патча 9.2.0.5, CORE компонент будет иметь версию 9.2.0.6 (соответсвенно после патча 9.2.0.6 будет таже версия 9.2.0.6). Это странное поведение описанно на металинке
Doc ID Note:263792.1 9.2.0.5 Patch Set – Known Issues
Цитирую:

Пример:

также имеет смысле проверить информацию из dba_registry представления:
select COMP_NAME, VERSION, STATUS from dba_registry;
все компоненты должны иметь туже верисию что описанна в readme.html для последнего патча (раздел Patch Set Components). И все компоненты должны иметь статус VALID или LOADED (если вы не используете данный компонент).
Для примера:

———————————————————–

но самый простой способ – это посмотерть приглашение сервера при соединении с ним например через SQL*Plus

D:\Temp\>sqlplus XXX/XXX@XXX

SQL*Plus: Release 10.2.0.1.0 – Production on Tue Aug 29 19:06:10 2006

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.5.0 – 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.5.0 – Production

или

select version from v$instance;

Эти рекомендации применимы к Oracle RDBMS release 9.2, но частично могут быть полезны и на 8.x и на 10.x.

First step:

select banner from v$version;
all core library components must have same version (9.2.0.x).

with exception of – after installation 9.2.0.5, CORE component must have version 9.2.0.6 (after patch 9.2.0.6 have same version 9.2.0.6). This strange behavior was described in
Doc ID Note:263792.1 9.2.0.5 Patch Set – Known Issues
citation:

example:

also you can see information from dba_registry view:
select COMP_NAME, VERSION, STATUS from dba_registry;
all components must have version which described in readme.html for last patch (chapter Patch Set Components). And all components must be VALID or LOADED (if you don’t use this component).
For example:

———————————————————–

but simpler way it is check welcome message from oracle server then you connect via SQL*Plus

D:\Temp\>sqlplus XXX/XXX@XXX

SQL*Plus: Release 10.2.0.1.0 – Production on Tue Aug 29 19:06:10 2006

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.5.0 – 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.5.0 – Production

select version from v$instance;

This «how-to» note only for Oracle RDBMS release 9.2, but partly can be useful on 8.x and 10.x.

User locks in Oracle

slookin — Fri, 18 Aug 2006 18:29:48 +0000

As we know, we can use dbms_lock package to manage our application locks. For example we can create «lock» for synchronize logic in application or you can «lock» your external resources (file handler, network sockets etc).

You can use different modes for lock your user resource:

nl -> «NuLl»
ss -> «Sub Shared»
sx -> «Sub eXclusive»
s -> «Shared»
ssx -> «Shared Sub eXclusive»,
x -> «eXclusive»

The following table is important to understand difference between lock modes:

If one process «held» lock, and other try to get lock – it get result from this table:

Also you can manage timeout to get lock, if resource locked your process will wait during «timeout».

For example:

The first process create lock to resource, because resource is free. (for example mode S)

Second process try to get lock with short timeout and incompatible lock mode (X) , it return value 1 – TimeOut.

Third process has log timeout and it create new lock after all previous lock was released.

Fourth process create new user lock because it has compatible lock mode. (for example S.

For monitoring user locks you should use:

dba_lock view (or v$lock),
DBMS_LOCK_ALLOCATED view
v$session view
UTLLOCKT.SQL script

documentation:

version: Oracle 9.2